This invention is directed to larger umbrellas commonly used for shading in outdoor settings such as parties, pool sides, and outdoor dining areas. It is collapsible in the sense of being retractable for storage, and deployable to its working configurations.
The working configuration of this invention is a dihedral canopy structure, folded along a dihedral edge. The dihedral angle is adjustable, and at one extreme may be 180 degrees (a flat plane), although the selected dihedral angle will most usually be less, resulting in two slanted panels, often with about 120 degrees included between them.
Such structures are usually mounted on stands and are subject to substantial wind loads which might overturn them. It is customary to provide a vent port in the canopy to reduce the differential pressure across it. In ordinary umbrellas, the size of the vent port must be kept quite small. It is an object of this invention to provide an arrangement in which the vent port can be made much larger by providing a vent cover whose deployed configuration is established by dedicated adjustable structure to assure that the vent cover will remain reliably open and in place, both to provide the vent function and to assure that the vent cover will reliably overhang the vent port.
There results an umbrella with a desirable and attractive configuration with an improved vent system in a conveniently-attained deployed condition, and which can readily be retracted to a conveniently carried and stored configuration.